Brown dye.



.UNTTED TATE PATENT @FFTCJE.

MYR'IIL KAI-IN, 0F ELBERFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN VQRIVI. FRIEDE. BAYER & (30., OF ELBERFELD, GERMANY, A CORPORATION OF GERMANY.

BROWN DYE.

No Drawing.

To all whom it may concern:

Be it known that I, Mrn'rIL KAHN, doctor of philosphy, chemist, citizen of the German Empire, residing at Elberfeld, Germany, have invented new and useful Improvements in Brown Dyestutl, of which the following is a specification.

invention relates to the manufacture and production of new brown disazo dyestuffs which can be obtained by combining the tetraZo compounds of meta-diaminodi phenylurea with one molecule of a metatoluylenediamin sulfonic acid and with one molecule of any other azo dyestuff component. The dyes thus obtained are in the shape of their alkaline salts brown powders soluble in water with a brown color; upon reduction with stannous chlorid and hydrochloric acid they are decomposed, carbonic acid, meta-phenylenediamin, triaminotoluene sulfonic acid and an amin being obtained. They are valuable brown substantive dyestufl's, which possess an extraordinary affinity for cotton. They can be developed after dyeing with diazotized para-nitranilin. In this way ver full brown shades are obtained, which can be discharged a splendid white with discharging agents. The fastness to washing of these shades is very good.

In order to illustrate the new process more fully the following example is given, the parts being by weight :2l.2 parts of metaliaminodiphenylnrea are dissolved in 1200 parts of water and 100 parts of a 30 per cent. hydrochloric acid. It is then diazotized in the usual manner with a solution of 14L parts of sodium nitrite in 500 parts of water. A solution of 20.2 parts of meta-toluylene diamin sulfonic acid (CH zNH zNl l z SO,,H:1:2:4:5) in 500 parts of water is added which solution contains an excess of sodium carbonate. The intermediate compound separates out. Its formation is complete after a short time. Subsequently an aqueous solution of 11 parts of meta-phenylenediamin is added to the mass of the reaction which is then stirred for about 1012 hours. The dye is filtered off and dried. It is, after being dried and pulverized, in the Specification of Letters Patent.

Application filed May 18, 1909.

Patented Jan. iii, 191w.

Serial No. 496,845.

shape of its sodium salt a brown powder soluble in hot water with a yellowisl1brown color and soluble in concentrated sulfuric acid with a yellowish-brown color; upon reduction with stannous chlorid and hydrochloric acid the dye is split up into carbonic acid, meta-phenylenediamin, triaminobenzene and triaminotoluene sulfonic acid. It dyes cot-ton brown shades which after combination with diazotized para-nitranilin on the fiber change into dark-brown shades fast to Washing and leaving after being discharged a pure white.

The process is carried out in an analogous manner on using other of the above mentioned components, 6. g. another metatoluylenediamin sulfonic acid or metaaminophenol, chloro-ineta-phenylenediamin (NH NH Cl-1 :3 :4), resorcin, metatoluylenediamin as second components.

I claim:

1. The herein-described new disazo dyestuffs obtainable from meta-diaminodiphenylurea, n1eta-toluylenediamin sulfonic acid and a suitable azo dyestuif component, which dyestuffs are, after being dried and pulverized, in the shape of their alkaline salts brown powders soluble in hot water with a brown color; yielding upon reduction with stannous chlorid and hydrochloric acid carbonic acid, meta-phenylenediamin, triaminotoluene sulfonic acid and an amin; and dyeing cotton brown shades, which after being developed on the fiber with diazoti ed paranitranilin are fast to washing and leaving after being discharged a pure white, substantially as described.

2. The herein described new disazo dye stuff obtainable from meta-dian1inodiphenylurea, meta-toluylenediamin sulfonic acid and meta-phenylene :liamin, which dyestuff is, after being dried and pulverized, in the shape of its sodium salt a brown powder soluble in hot water with a yellowish-brown color and soluble in concentrated sulfuric acid with a yellowish-brown color; yielding upon reduction with stannous chlorid and hydrochloric acid carbonic acid, meta-phenylenediamin, triaminobenzene and triaminotoluene snlfonic acid; and dyeing cot- In testimony whereof I have hereunto set ton brown shades, Which after being develmy hand in the presence of tWo subscribing oped on the fiber With diazotized para- Witnesses.

nitranilin change into dark-brown shades MYRTIL KAHN. TL. s1 5 fast to Washing and leaving after being dis- Witnesses:

charged a pure White, substantially as de- OTTO'KGNIG,

scribed. C. J. WRIGHT. 

